Control moment gyroscope

Abstract

A control moment gyroscope (CMG) is provided for deployment on a spacecraft. The CMG includes an inner gimbal assembly (IGA), which, in turn, includes an IGA housing, a rotor rotatably coupled to the IGA housing, and a spin motor coupled to the IGA housing and configured to rotate the rotor about a spin axis. The CMG further comprises a stator assembly, which includes: (i) a stator assembly housing rotatably coupled to the IGA housing, and (ii) a torque module assembly coupled to the stator assembly housing and configured to rotate the IGA about a gimbal axis. A gimbal bearing is disposed between the IGA housing and the stator assembly housing. The gimbal bearing resides between the spin axis and the torque module assembly such that the distance between the gimbal bearing and the spin axis is less than the distance between the gimbal bearing and the torque module assembly.

Description

TECHNICAL FIELD[0001]The present invention relates generally to rotational devices and, more particularly, to control moment gyroscope including a stator assembly having a large bore gimbal bearing.BACKGROUND[0002]Control moment gyroscopes (CMGs) are commonly employed in satellite attitude control systems. A generalized CMG may comprise a housing that supports an inner gimbal assembly (IGA). The IGA includes a rotor comprising an inertial element (e.g., a rotating ring or cylinder) coupled to a shaft. Spin bearings are disposed around the shaft ends to facilitate the rotational movement of the shaft, which may be rotated about a spin axis by a spin motor. The IGA, in turn, may be rotated about a gimbal axis by a torque module assembly (TMA) mounted to a first end of the CMG housing. To facilitate the rotational movement of the IGA, gimbal bearings are disposed between the IGA and the CMG housing. A signal module assembly (SMA) may also be mounted to a second portion of the CMG housi...

AI Technical Summary

Benefits of technology

[0006]A control moment gyroscope (CMG) is provided for deployment on a spacecraft. The CMG includes an inner gimbal assembly (IGA), which, in turn, includes an IGA housing, a rotor rotatably coupled to the IGA housing, and a spin motor coupled to the IGA housing and configured to rotate the rotor about a spin axis. The CMG further comprises a stator assembly, which includes: (i) a stator assembly housing rotatably coupled to the IGA housing,

Problems solved by technology

This notwithstanding, conventional CMGs often provide a relatively lengthy and inefficient rotor-to-spacecraft load path.

The IGA housing is typically thin-walled and flexible and, consequently, relatively poor at transmitting torque and conducting heat to the spacecraft.

Although certain measures may be taken to stiffen the IGA housing (e.g., thickening the housing walls or providing ribs therein), these measures add surplus weight to the CMG.

Furthermore, because the TMA and the SMA are mounted to opposite ends of the IGA housing, an undesirable twisting of the IGA housing and other components of the CMG is induced when the IGA is rotated about the gimbal axis.

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